c# - 如何测试自动命名状态机？

Question

我正在尝试为自动命名状态机编写测试，但我在正确完成它时遇到了一些麻烦，而且我发现的文档很少。

这是我目前拥有的一项测试:

[TestFixture]
public class MyProcessStateMachineTests
{
    InMemoryTestHarness _Harness;
    MyProcessStateMachine _Machine;
    StateMachineSagaTestHarness<MyProcess, MyProcessStateMachine> _Saga;

    [OneTimeSetUp]
    public void ConfigureMessages()
    {
        MessageCorrelation.UseCorrelationId<RequestMyDetails>(x => x.CorrelationId);
        MessageCorrelation.UseCorrelationId<FileAttached>(x => x.CorrelationId);
        MessageCorrelation.UseCorrelationId<PDFGenerated>(x => x.CorrelationId);
        MessageCorrelation.UseCorrelationId<CustomerAttachFile>(x => x.CorrelationId);
        MessageCorrelation.UseCorrelationId<AddCustomerNote>(x => x.CorrelationId);
        MessageCorrelation.UseCorrelationId<EmailPublished>(x => x.CorrelationId);
    }


    [SetUp]
    public void InitializeTestHarness()
    {
        _Harness = new InMemoryTestHarness();
        _Machine = new MyProcessStateMachine( /* snip */ );
        _Saga = _Harness.StateMachineSaga<MyProcess, MyProcessStateMachine>(_Machine);

        _Harness.Start().Wait();
    }

    [TearDown]
    public void StopTestHarness()
    {
        _Harness.Stop();
    }


    [Test]
    public async Task ShouldAttachToCustomer()
    {
        var sagaId = Guid.NewGuid();
        var custId = Guid.NewGuid();
        var fileAttached = BuildFileAttachedMessage(sagaId);

        await _Harness.InputQueueSendEndpoint.Send(BuildStartMessage(sagaId));
        await _Harness.InputQueueSendEndpoint.Send(BuildDetailsReceivedMessage(sagaId));
        await _Harness.InputQueueSendEndpoint.Send(BuildPdfGeneratedMessage(sagaId));
        await _Harness.InputQueueSendEndpoint.Send(fileAttached);

        // Next line is based on [the answer here][1]
        // Once the above messages are all consumed and processed,
        // the state machine should be in AwaitingEmail state
        await _Saga.Match(x =>
            x.CorrelationId == sagaId
                && x.CurrentState == _Machine.AwaitingEmail.Name,
            new TimeSpan(0, 0, 30));

        // Grab the instance and Assert stuff...
    }

    // Snip...
}

鉴于 _Saga.Match 调用找到匹配项，我希望所有消息都已处理，我应该能够获取我的状态机实例和已发布的事件并检查它们的值 - 但事实并非如此。当我在 fixture 中运行测试时，有时我得到的实例已经消耗并发布了预期的消息；有时它还不完全存在。

我尝试使用以下方式获取我的实例:

var inst = _Saga.Sagas.FirstOrDefault(x => x.Saga.CorrelationId == sagaId);

或通过以下方式获取已发布的事件:

var test = _Harness.Published
    .FirstOrDefault(x => x.MessageType == typeof(IAttachFile) && x.Context.CorrelationId == sagaId);

但是对 Match 的调用是否成功并不重要，状态机实例(和发布的事件)并不总是存在。

我假设来自 Automatonymous、MassTransit 或测试工具的异步进程导致了不一致。有帮助吗？

使用 MassTransit、MassTransit.Automatonymous 和 MassTransit.TestFramework 5.1.2.1528、Automatonymous 4.1.1.102 进行测试，

编辑:

进一步审查，我发现当我遇到问题时，调用 Match( ... )没有成功 - 它超时了。 (我一直错误地假设超时会引发异常。)

Answer 1

对于遇到相同问题的任何人:您尝试获取实例的方式

var inst = _Saga.Sagas.FirstOrDefault(x => x.Saga.CorrelationId == sagaId);

可以这样固定

var instanceIds = await _sagaHarness.Match(
    instance => instance.CorrelationId == sagaId
        && instance.CurrentState == _machine.Working.Name,
        new TimeSpan(0, 0, 30));

将预期状态包含在条件中很重要。仅通过 correlationid 获取实例然后测试 CurrentState 可能会失败，因为设置状态(saga 执行是异步的)可能需要一些时间。查看完整示例 https://github.com/balintn22/AutomatonymousTestExample